Merge branch 'netlink-allow-NLA_BINARY-length-range-validation'

Johannes Berg says:

====================
netlink: allow NLA_BINARY length range validation

In quite a few places (perhaps particularly in wireless) we need to
validation an NLA_BINARY attribute with both a minimum and a maximum
length. Currently, we can do either of the two, but not both, given
that we have NLA_MIN_LEN (minimum length) and NLA_BINARY (maximum).

Extend the range mechanisms that we use for integer validation to
apply to NLA_BINARY as well.

After converting everything to use NLA_POLICY_MIN_LEN() we can thus
get rid of the NLA_MIN_LEN type since that's now a special case of
NLA_BINARY with a minimum length validation. Similarly, NLA_EXACT_LEN
can be specified using NLA_POLICY_EXACT_LEN() and also maps to the
new NLA_BINARY validation (min == max == desired length).

Finally, NLA_POLICY_EXACT_LEN_WARN() also gets to be a somewhat
special case of this.

I haven't included the patch here now that converts nl82011 to use
this because it doesn't apply without another cleanup patch, but
we can remove a number of hand-coded min/max length checks and get
better error messages from the general validation code while doing
that.

As I had originally built the netlink policy export to userspace in
a way that has min/max length for NLA_BINARY (for the types that we
used to call NLA_MIN_LEN, NLA_BINARY and NLA_EXACT_LEN) anyway, it
doesn't really change anything there except that now there's a chance
that userspace sees min length < max length, which previously wasn't
possible.

v2:
 * fix the min<max comment to correctly say min<=max
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/macsec.c

@@ -1611,7 +1611,7 @@ static const struct nla_policy macsec_genl_rxsc_policy[NUM_MACSEC_RXSC_ATTR] = {
 static const struct nla_policy macsec_genl_sa_policy[NUM_MACSEC_SA_ATTR] = {
 	[MACSEC_SA_ATTR_AN] = { .type = NLA_U8 },
 	[MACSEC_SA_ATTR_ACTIVE] = { .type = NLA_U8 },
-	[MACSEC_SA_ATTR_PN] = { .type = NLA_MIN_LEN, .len = 4 },
+	[MACSEC_SA_ATTR_PN] = NLA_POLICY_MIN_LEN(4),
 	[MACSEC_SA_ATTR_KEYID] = { .type = NLA_BINARY,
 				   .len = MACSEC_KEYID_LEN, },
 	[MACSEC_SA_ATTR_KEY] = { .type = NLA_BINARY,

drivers/net/wireguard/netlink.c

@@ -22,8 +22,8 @@ static struct genl_family genl_family;
 static const struct nla_policy device_policy[WGDEVICE_A_MAX + 1] = {
 	[WGDEVICE_A_IFINDEX]		= { .type = NLA_U32 },
 	[WGDEVICE_A_IFNAME]		= { .type = NLA_NUL_STRING, .len = IFNAMSIZ - 1 },
-	[WGDEVICE_A_PRIVATE_KEY]	= { .type = NLA_EXACT_LEN, .len = NOISE_PUBLIC_KEY_LEN },
-	[WGDEVICE_A_PUBLIC_KEY]		= { .type = NLA_EXACT_LEN, .len = NOISE_PUBLIC_KEY_LEN },
+	[WGDEVICE_A_PRIVATE_KEY]	= NLA_POLICY_EXACT_LEN(NOISE_PUBLIC_KEY_LEN),
+	[WGDEVICE_A_PUBLIC_KEY]		= NLA_POLICY_EXACT_LEN(NOISE_PUBLIC_KEY_LEN),
 	[WGDEVICE_A_FLAGS]		= { .type = NLA_U32 },
 	[WGDEVICE_A_LISTEN_PORT]	= { .type = NLA_U16 },
 	[WGDEVICE_A_FWMARK]		= { .type = NLA_U32 },
@@ -31,12 +31,12 @@ static const struct nla_policy device_policy[WGDEVICE_A_MAX + 1] = {
 };
 
 static const struct nla_policy peer_policy[WGPEER_A_MAX + 1] = {
-	[WGPEER_A_PUBLIC_KEY]				= { .type = NLA_EXACT_LEN, .len = NOISE_PUBLIC_KEY_LEN },
-	[WGPEER_A_PRESHARED_KEY]			= { .type = NLA_EXACT_LEN, .len = NOISE_SYMMETRIC_KEY_LEN },
+	[WGPEER_A_PUBLIC_KEY]				= NLA_POLICY_EXACT_LEN(NOISE_PUBLIC_KEY_LEN),
+	[WGPEER_A_PRESHARED_KEY]			= NLA_POLICY_EXACT_LEN(NOISE_SYMMETRIC_KEY_LEN),
 	[WGPEER_A_FLAGS]				= { .type = NLA_U32 },
-	[WGPEER_A_ENDPOINT]				= { .type = NLA_MIN_LEN, .len = sizeof(struct sockaddr) },
+	[WGPEER_A_ENDPOINT]				= NLA_POLICY_MIN_LEN(sizeof(struct sockaddr)),
 	[WGPEER_A_PERSISTENT_KEEPALIVE_INTERVAL]	= { .type = NLA_U16 },
-	[WGPEER_A_LAST_HANDSHAKE_TIME]			= { .type = NLA_EXACT_LEN, .len = sizeof(struct __kernel_timespec) },
+	[WGPEER_A_LAST_HANDSHAKE_TIME]			= NLA_POLICY_EXACT_LEN(sizeof(struct __kernel_timespec)),
 	[WGPEER_A_RX_BYTES]				= { .type = NLA_U64 },
 	[WGPEER_A_TX_BYTES]				= { .type = NLA_U64 },
 	[WGPEER_A_ALLOWEDIPS]				= { .type = NLA_NESTED },
@@ -45,7 +45,7 @@ static const struct nla_policy peer_policy[WGPEER_A_MAX + 1] = {
 
 static const struct nla_policy allowedip_policy[WGALLOWEDIP_A_MAX + 1] = {
 	[WGALLOWEDIP_A_FAMILY]		= { .type = NLA_U16 },
-	[WGALLOWEDIP_A_IPADDR]		= { .type = NLA_MIN_LEN, .len = sizeof(struct in_addr) },
+	[WGALLOWEDIP_A_IPADDR]		= NLA_POLICY_MIN_LEN(sizeof(struct in_addr)),
 	[WGALLOWEDIP_A_CIDR_MASK]	= { .type = NLA_U8 }
 };
 

include/net/netlink.h

@@ -181,8 +181,6 @@ enum {
 	NLA_S64,
 	NLA_BITFIELD32,
 	NLA_REJECT,
-	NLA_EXACT_LEN,
-	NLA_MIN_LEN,
 	__NLA_TYPE_MAX,
 };
 
@@ -199,11 +197,11 @@ struct netlink_range_validation_signed {
 enum nla_policy_validation {
 	NLA_VALIDATE_NONE,
 	NLA_VALIDATE_RANGE,
+	NLA_VALIDATE_RANGE_WARN_TOO_LONG,
 	NLA_VALIDATE_MIN,
 	NLA_VALIDATE_MAX,
 	NLA_VALIDATE_RANGE_PTR,
 	NLA_VALIDATE_FUNCTION,
-	NLA_VALIDATE_WARN_TOO_LONG,
 };
 
 /**
@@ -222,7 +220,7 @@ enum nla_policy_validation {
  *    NLA_NUL_STRING       Maximum length of string (excluding NUL)
  *    NLA_FLAG             Unused
  *    NLA_BINARY           Maximum length of attribute payload
- *    NLA_MIN_LEN          Minimum length of attribute payload
+ *                         (but see also below with the validation type)
  *    NLA_NESTED,
  *    NLA_NESTED_ARRAY     Length verification is done by checking len of
  *                         nested header (or empty); len field is used if
@@ -237,11 +235,6 @@ enum nla_policy_validation {
  *                         just like "All other"
  *    NLA_BITFIELD32       Unused
  *    NLA_REJECT           Unused
- *    NLA_EXACT_LEN        Attribute should have exactly this length, otherwise
- *                         it is rejected or warned about, the latter happening
- *                         if and only if the `validation_type' is set to
- *                         NLA_VALIDATE_WARN_TOO_LONG.
- *    NLA_MIN_LEN          Minimum length of attribute payload
  *    All other            Minimum length of attribute payload
  *
  * Meaning of validation union:
@@ -296,6 +289,11 @@ enum nla_policy_validation {
  *                         pointer to a struct netlink_range_validation_signed
  *                         that indicates the min/max values.
  *                         Use NLA_POLICY_FULL_RANGE_SIGNED().
+ *
+ *    NLA_BINARY           If the validation type is like the ones for integers
+ *                         above, then the min/max length (not value like for
+ *                         integers) of the attribute is enforced.
+ *
  *    All other            Unused - but note that it's a union
  *
  * Meaning of `validate' field, use via NLA_POLICY_VALIDATE_FN:
@@ -309,7 +307,7 @@ enum nla_policy_validation {
  * static const struct nla_policy my_policy[ATTR_MAX+1] = {
  * 	[ATTR_FOO] = { .type = NLA_U16 },
  *	[ATTR_BAR] = { .type = NLA_STRING, .len = BARSIZ },
- *	[ATTR_BAZ] = { .type = NLA_EXACT_LEN, .len = sizeof(struct mystruct) },
+ *	[ATTR_BAZ] = NLA_POLICY_EXACT_LEN(sizeof(struct mystruct)),
  *	[ATTR_GOO] = NLA_POLICY_BITFIELD32(myvalidflags),
  * };
  */
@@ -335,9 +333,10 @@ struct nla_policy {
 		 * nesting validation starts here.
 		 *
 		 * Additionally, it means that NLA_UNSPEC is actually NLA_REJECT
-		 * for any types >= this, so need to use NLA_MIN_LEN to get the
-		 * previous pure { .len = xyz } behaviour. The advantage of this
-		 * is that types not specified in the policy will be rejected.
+		 * for any types >= this, so need to use NLA_POLICY_MIN_LEN() to
+		 * get the previous pure { .len = xyz } behaviour. The advantage
+		 * of this is that types not specified in the policy will be
+		 * rejected.
 		 *
 		 * For completely new families it should be set to 1 so that the
 		 * validation is enforced for all attributes. For existing ones
@@ -349,12 +348,6 @@ struct nla_policy {
 	};
 };
 
-#define NLA_POLICY_EXACT_LEN(_len)	{ .type = NLA_EXACT_LEN, .len = _len }
-#define NLA_POLICY_EXACT_LEN_WARN(_len) \
-	{ .type = NLA_EXACT_LEN, .len = _len, \
-	  .validation_type = NLA_VALIDATE_WARN_TOO_LONG, }
-#define NLA_POLICY_MIN_LEN(_len)	{ .type = NLA_MIN_LEN, .len = _len }
-
 #define NLA_POLICY_ETH_ADDR		NLA_POLICY_EXACT_LEN(ETH_ALEN)
 #define NLA_POLICY_ETH_ADDR_COMPAT	NLA_POLICY_EXACT_LEN_WARN(ETH_ALEN)
 
@@ -370,19 +363,21 @@ struct nla_policy {
 	{ .type = NLA_BITFIELD32, .bitfield32_valid = valid }
 
 #define __NLA_ENSURE(condition) BUILD_BUG_ON_ZERO(!(condition))
-#define NLA_ENSURE_UINT_TYPE(tp)			\
+#define NLA_ENSURE_UINT_OR_BINARY_TYPE(tp)		\
 	(__NLA_ENSURE(tp == NLA_U8 || tp == NLA_U16 ||	\
 		      tp == NLA_U32 || tp == NLA_U64 ||	\
-		      tp == NLA_MSECS) + tp)
+		      tp == NLA_MSECS ||		\
+		      tp == NLA_BINARY) + tp)
 #define NLA_ENSURE_SINT_TYPE(tp)			\
 	(__NLA_ENSURE(tp == NLA_S8 || tp == NLA_S16  ||	\
 		      tp == NLA_S32 || tp == NLA_S64) + tp)
-#define NLA_ENSURE_INT_TYPE(tp)				\
+#define NLA_ENSURE_INT_OR_BINARY_TYPE(tp)		\
 	(__NLA_ENSURE(tp == NLA_S8 || tp == NLA_U8 ||	\
 		      tp == NLA_S16 || tp == NLA_U16 ||	\
 		      tp == NLA_S32 || tp == NLA_U32 ||	\
 		      tp == NLA_S64 || tp == NLA_U64 ||	\
-		      tp == NLA_MSECS) + tp)
+		      tp == NLA_MSECS ||		\
+		      tp == NLA_BINARY) + tp)
 #define NLA_ENSURE_NO_VALIDATION_PTR(tp)		\
 	(__NLA_ENSURE(tp != NLA_BITFIELD32 &&		\
 		      tp != NLA_REJECT &&		\
@@ -390,14 +385,14 @@ struct nla_policy {
 		      tp != NLA_NESTED_ARRAY) + tp)
 
 #define NLA_POLICY_RANGE(tp, _min, _max) {		\
-	.type = NLA_ENSURE_INT_TYPE(tp),		\
+	.type = NLA_ENSURE_INT_OR_BINARY_TYPE(tp),	\
 	.validation_type = NLA_VALIDATE_RANGE,		\
 	.min = _min,					\
 	.max = _max					\
 }
 
 #define NLA_POLICY_FULL_RANGE(tp, _range) {		\
-	.type = NLA_ENSURE_UINT_TYPE(tp),		\
+	.type = NLA_ENSURE_UINT_OR_BINARY_TYPE(tp),	\
 	.validation_type = NLA_VALIDATE_RANGE_PTR,	\
 	.range = _range,				\
 }
@@ -409,13 +404,13 @@ struct nla_policy {
 }
 
 #define NLA_POLICY_MIN(tp, _min) {			\
-	.type = NLA_ENSURE_INT_TYPE(tp),		\
+	.type = NLA_ENSURE_INT_OR_BINARY_TYPE(tp),	\
 	.validation_type = NLA_VALIDATE_MIN,		\
 	.min = _min,					\
 }
 
 #define NLA_POLICY_MAX(tp, _max) {			\
-	.type = NLA_ENSURE_INT_TYPE(tp),		\
+	.type = NLA_ENSURE_INT_OR_BINARY_TYPE(tp),	\
 	.validation_type = NLA_VALIDATE_MAX,		\
 	.max = _max,					\
 }
@@ -427,6 +422,15 @@ struct nla_policy {
 	.len = __VA_ARGS__ + 0,				\
 }
 
+#define NLA_POLICY_EXACT_LEN(_len)	NLA_POLICY_RANGE(NLA_BINARY, _len, _len)
+#define NLA_POLICY_EXACT_LEN_WARN(_len) {			\
+	.type = NLA_BINARY,					\
+	.validation_type = NLA_VALIDATE_RANGE_WARN_TOO_LONG,	\
+	.min = _len,						\
+	.max = _len						\
+}
+#define NLA_POLICY_MIN_LEN(_len)	NLA_POLICY_MIN(NLA_BINARY, _len)
+
 /**
  * struct nl_info - netlink source information
  * @nlh: Netlink message header of original request

lib/nlattr.c

@@ -124,6 +124,7 @@ void nla_get_range_unsigned(const struct nla_policy *pt,
 		range->max = U8_MAX;
 		break;
 	case NLA_U16:
+	case NLA_BINARY:
 		range->max = U16_MAX;
 		break;
 	case NLA_U32:
@@ -140,6 +141,7 @@ void nla_get_range_unsigned(const struct nla_policy *pt,
 
 	switch (pt->validation_type) {
 	case NLA_VALIDATE_RANGE:
+	case NLA_VALIDATE_RANGE_WARN_TOO_LONG:
 		range->min = pt->min;
 		range->max = pt->max;
 		break;
@@ -157,9 +159,10 @@ void nla_get_range_unsigned(const struct nla_policy *pt,
 	}
 }
 
-static int nla_validate_int_range_unsigned(const struct nla_policy *pt,
+static int nla_validate_range_unsigned(const struct nla_policy *pt,
 				       const struct nlattr *nla,
-					   struct netlink_ext_ack *extack)
+				       struct netlink_ext_ack *extack,
+				       unsigned int validate)
 {
 	struct netlink_range_validation range;
 	u64 value;
@@ -178,15 +181,39 @@ static int nla_validate_int_range_unsigned(const struct nla_policy *pt,
 	case NLA_MSECS:
 		value = nla_get_u64(nla);
 		break;
+	case NLA_BINARY:
+		value = nla_len(nla);
+		break;
 	default:
 		return -EINVAL;
 	}
 
 	nla_get_range_unsigned(pt, &range);
 
+	if (pt->validation_type == NLA_VALIDATE_RANGE_WARN_TOO_LONG &&
+	    pt->type == NLA_BINARY && value > range.max) {
+		pr_warn_ratelimited("netlink: '%s': attribute type %d has an invalid length.\n",
+				    current->comm, pt->type);
+		if (validate & NL_VALIDATE_STRICT_ATTRS) {
+			NL_SET_ERR_MSG_ATTR(extack, nla,
+					    "invalid attribute length");
+			return -EINVAL;
+		}
+
+		/* this assumes min <= max (don't validate against min) */
+		return 0;
+	}
+
 	if (value < range.min || value > range.max) {
+		bool binary = pt->type == NLA_BINARY;
+
+		if (binary)
+			NL_SET_ERR_MSG_ATTR(extack, nla,
+					    "binary attribute size out of range");
+		else
 			NL_SET_ERR_MSG_ATTR(extack, nla,
 					    "integer out of range");
+
 		return -ERANGE;
 	}
 
@@ -274,7 +301,8 @@ static int nla_validate_int_range_signed(const struct nla_policy *pt,
 
 static int nla_validate_int_range(const struct nla_policy *pt,
 				  const struct nlattr *nla,
-				  struct netlink_ext_ack *extack)
+				  struct netlink_ext_ack *extack,
+				  unsigned int validate)
 {
 	switch (pt->type) {
 	case NLA_U8:
@@ -282,7 +310,8 @@ static int nla_validate_int_range(const struct nla_policy *pt,
 	case NLA_U32:
 	case NLA_U64:
 	case NLA_MSECS:
-		return nla_validate_int_range_unsigned(pt, nla, extack);
+	case NLA_BINARY:
+		return nla_validate_range_unsigned(pt, nla, extack, validate);
 	case NLA_S8:
 	case NLA_S16:
 	case NLA_S32:
@@ -313,10 +342,7 @@ static int validate_nla(const struct nlattr *nla, int maxtype,
 
 	BUG_ON(pt->type > NLA_TYPE_MAX);
 
-	if ((nla_attr_len[pt->type] && attrlen != nla_attr_len[pt->type]) ||
-	    (pt->type == NLA_EXACT_LEN &&
-	     pt->validation_type == NLA_VALIDATE_WARN_TOO_LONG &&
-	     attrlen != pt->len)) {
+	if (nla_attr_len[pt->type] && attrlen != nla_attr_len[pt->type]) {
 		pr_warn_ratelimited("netlink: '%s': attribute type %d has an invalid length.\n",
 				    current->comm, type);
 		if (validate & NL_VALIDATE_STRICT_ATTRS) {
@@ -449,19 +475,10 @@ static int validate_nla(const struct nlattr *nla, int maxtype,
 					    "Unsupported attribute");
 			return -EINVAL;
 		}
-		/* fall through */
-	case NLA_MIN_LEN:
 		if (attrlen < pt->len)
 			goto out_err;
 		break;
 
-	case NLA_EXACT_LEN:
-		if (pt->validation_type != NLA_VALIDATE_WARN_TOO_LONG) {
-			if (attrlen != pt->len)
-				goto out_err;
-			break;
-		}
-		/* fall through */
 	default:
 		if (pt->len)
 			minlen = pt->len;
@@ -479,9 +496,10 @@ static int validate_nla(const struct nlattr *nla, int maxtype,
 		break;
 	case NLA_VALIDATE_RANGE_PTR:
 	case NLA_VALIDATE_RANGE:
+	case NLA_VALIDATE_RANGE_WARN_TOO_LONG:
 	case NLA_VALIDATE_MIN:
 	case NLA_VALIDATE_MAX:
-		err = nla_validate_int_range(pt, nla, extack);
+		err = nla_validate_int_range(pt, nla, extack, validate);
 		if (err)
 			return err;
 		break;

net/bridge/br_netlink.c

@@ -1095,8 +1095,8 @@ static const struct nla_policy br_policy[IFLA_BR_MAX + 1] = {
 	[IFLA_BR_MCAST_IGMP_VERSION] = { .type = NLA_U8 },
 	[IFLA_BR_MCAST_MLD_VERSION] = { .type = NLA_U8 },
 	[IFLA_BR_VLAN_STATS_PER_PORT] = { .type = NLA_U8 },
-	[IFLA_BR_MULTI_BOOLOPT] = { .type = NLA_EXACT_LEN,
-				    .len = sizeof(struct br_boolopt_multi) },
+	[IFLA_BR_MULTI_BOOLOPT] =
+		NLA_POLICY_EXACT_LEN(sizeof(struct br_boolopt_multi)),
 };
 
 static int br_changelink(struct net_device *brdev, struct nlattr *tb[],

net/bridge/br_vlan.c

@@ -1884,8 +1884,8 @@ static int br_vlan_rtm_dump(struct sk_buff *skb, struct netlink_callback *cb)
 }
 
 static const struct nla_policy br_vlan_db_policy[BRIDGE_VLANDB_ENTRY_MAX + 1] = {
-	[BRIDGE_VLANDB_ENTRY_INFO]	= { .type = NLA_EXACT_LEN,
-					    .len = sizeof(struct bridge_vlan_info) },
+	[BRIDGE_VLANDB_ENTRY_INFO]	=
+		NLA_POLICY_EXACT_LEN(sizeof(struct bridge_vlan_info)),
 	[BRIDGE_VLANDB_ENTRY_RANGE]	= { .type = NLA_U16 },
 	[BRIDGE_VLANDB_ENTRY_STATE]	= { .type = NLA_U8 },
 	[BRIDGE_VLANDB_ENTRY_TUNNEL_INFO] = { .type = NLA_NESTED },

net/mptcp/pm_netlink.c

@@ -384,8 +384,8 @@ mptcp_pm_addr_policy[MPTCP_PM_ADDR_ATTR_MAX + 1] = {
 	[MPTCP_PM_ADDR_ATTR_FAMILY]	= { .type	= NLA_U16,	},
 	[MPTCP_PM_ADDR_ATTR_ID]		= { .type	= NLA_U8,	},
 	[MPTCP_PM_ADDR_ATTR_ADDR4]	= { .type	= NLA_U32,	},
-	[MPTCP_PM_ADDR_ATTR_ADDR6]	= { .type	= NLA_EXACT_LEN,
-					    .len   = sizeof(struct in6_addr), },
+	[MPTCP_PM_ADDR_ATTR_ADDR6]	=
+		NLA_POLICY_EXACT_LEN(sizeof(struct in6_addr)),
 	[MPTCP_PM_ADDR_ATTR_PORT]	= { .type	= NLA_U16	},
 	[MPTCP_PM_ADDR_ATTR_FLAGS]	= { .type	= NLA_U32	},
 	[MPTCP_PM_ADDR_ATTR_IF_IDX]     = { .type	= NLA_S32	},

net/netlink/policy.c

@@ -251,12 +251,6 @@ int netlink_policy_dump_write(struct sk_buff *skb, unsigned long _state)
 				pt->bitfield32_valid))
 			goto nla_put_failure;
 		break;
-	case NLA_EXACT_LEN:
-		type = NL_ATTR_TYPE_BINARY;
-		if (nla_put_u32(skb, NL_POLICY_TYPE_ATTR_MIN_LENGTH, pt->len) ||
-		    nla_put_u32(skb, NL_POLICY_TYPE_ATTR_MAX_LENGTH, pt->len))
-			goto nla_put_failure;
-		break;
 	case NLA_STRING:
 	case NLA_NUL_STRING:
 	case NLA_BINARY:
@@ -266,14 +260,26 @@ int netlink_policy_dump_write(struct sk_buff *skb, unsigned long _state)
 			type = NL_ATTR_TYPE_NUL_STRING;
 		else
 			type = NL_ATTR_TYPE_BINARY;
-		if (pt->len && nla_put_u32(skb, NL_POLICY_TYPE_ATTR_MAX_LENGTH,
-					   pt->len))
+
+		if (pt->validation_type != NLA_VALIDATE_NONE) {
+			struct netlink_range_validation range;
+
+			nla_get_range_unsigned(pt, &range);
+
+			if (range.min &&
+			    nla_put_u32(skb, NL_POLICY_TYPE_ATTR_MIN_LENGTH,
+					range.min))
 				goto nla_put_failure;
-		break;
-	case NLA_MIN_LEN:
-		type = NL_ATTR_TYPE_BINARY;
-		if (nla_put_u32(skb, NL_POLICY_TYPE_ATTR_MIN_LENGTH, pt->len))
+
+			if (range.max < U16_MAX &&
+			    nla_put_u32(skb, NL_POLICY_TYPE_ATTR_MAX_LENGTH,
+					range.max))
+				goto nla_put_failure;
+		} else if (pt->len &&
+			   nla_put_u32(skb, NL_POLICY_TYPE_ATTR_MAX_LENGTH,
+				       pt->len)) {
 			goto nla_put_failure;
+		}
 		break;
 	case NLA_FLAG:
 		type = NL_ATTR_TYPE_FLAG;

net/sched/act_ct.c

@@ -1039,7 +1039,7 @@ static int tcf_ct_act(struct sk_buff *skb, const struct tc_action *a,
 
 static const struct nla_policy ct_policy[TCA_CT_MAX + 1] = {
 	[TCA_CT_ACTION] = { .type = NLA_U16 },
-	[TCA_CT_PARMS] = { .type = NLA_EXACT_LEN, .len = sizeof(struct tc_ct) },
+	[TCA_CT_PARMS] = NLA_POLICY_EXACT_LEN(sizeof(struct tc_ct)),
 	[TCA_CT_ZONE] = { .type = NLA_U16 },
 	[TCA_CT_MARK] = { .type = NLA_U32 },
 	[TCA_CT_MARK_MASK] = { .type = NLA_U32 },
@@ -1049,10 +1049,8 @@ static const struct nla_policy ct_policy[TCA_CT_MAX + 1] = {
 				 .len = 128 / BITS_PER_BYTE },
 	[TCA_CT_NAT_IPV4_MIN] = { .type = NLA_U32 },
 	[TCA_CT_NAT_IPV4_MAX] = { .type = NLA_U32 },
-	[TCA_CT_NAT_IPV6_MIN] = { .type = NLA_EXACT_LEN,
-				  .len = sizeof(struct in6_addr) },
-	[TCA_CT_NAT_IPV6_MAX] = { .type = NLA_EXACT_LEN,
-				   .len = sizeof(struct in6_addr) },
+	[TCA_CT_NAT_IPV6_MIN] = NLA_POLICY_EXACT_LEN(sizeof(struct in6_addr)),
+	[TCA_CT_NAT_IPV6_MAX] = NLA_POLICY_EXACT_LEN(sizeof(struct in6_addr)),
 	[TCA_CT_NAT_PORT_MIN] = { .type = NLA_U16 },
 	[TCA_CT_NAT_PORT_MAX] = { .type = NLA_U16 },
 };

net/sched/act_ctinfo.c

@@ -144,9 +144,8 @@ static int tcf_ctinfo_act(struct sk_buff *skb, const struct tc_action *a,
 }
 
 static const struct nla_policy ctinfo_policy[TCA_CTINFO_MAX + 1] = {
-	[TCA_CTINFO_ACT]		  = { .type = NLA_EXACT_LEN,
-					      .len = sizeof(struct
-							    tc_ctinfo) },
+	[TCA_CTINFO_ACT]		  =
+		NLA_POLICY_EXACT_LEN(sizeof(struct tc_ctinfo)),
 	[TCA_CTINFO_ZONE]		  = { .type = NLA_U16 },
 	[TCA_CTINFO_PARMS_DSCP_MASK]	  = { .type = NLA_U32 },
 	[TCA_CTINFO_PARMS_DSCP_STATEMASK] = { .type = NLA_U32 },

net/sched/act_gate.c

@@ -159,8 +159,8 @@ static const struct nla_policy entry_policy[TCA_GATE_ENTRY_MAX + 1] = {
 };
 
 static const struct nla_policy gate_policy[TCA_GATE_MAX + 1] = {
-	[TCA_GATE_PARMS]		= { .len = sizeof(struct tc_gate),
-					    .type = NLA_EXACT_LEN },
+	[TCA_GATE_PARMS]		=
+		NLA_POLICY_EXACT_LEN(sizeof(struct tc_gate)),
 	[TCA_GATE_PRIORITY]		= { .type = NLA_S32 },
 	[TCA_GATE_ENTRY_LIST]		= { .type = NLA_NESTED },
 	[TCA_GATE_BASE_TIME]		= { .type = NLA_U64 },

net/wireless/nl80211.c

@@ -654,10 +654,8 @@ static const struct nla_policy nl80211_policy[NUM_NL80211_ATTR] = {
 	[NL80211_ATTR_RECEIVE_MULTICAST] = { .type = NLA_FLAG },
 	[NL80211_ATTR_WIPHY_FREQ_OFFSET] = NLA_POLICY_RANGE(NLA_U32, 0, 999),
 	[NL80211_ATTR_SCAN_FREQ_KHZ] = { .type = NLA_NESTED },
-	[NL80211_ATTR_HE_6GHZ_CAPABILITY] = {
-		.type = NLA_EXACT_LEN,
-		.len = sizeof(struct ieee80211_he_6ghz_capa),
-	},
+	[NL80211_ATTR_HE_6GHZ_CAPABILITY] =
+		NLA_POLICY_EXACT_LEN(sizeof(struct ieee80211_he_6ghz_capa)),
 };
 
 /* policy for the key attributes */
@@ -703,7 +701,7 @@ nl80211_wowlan_tcp_policy[NUM_NL80211_WOWLAN_TCP] = {
 	[NL80211_WOWLAN_TCP_DST_MAC] = NLA_POLICY_EXACT_LEN_WARN(ETH_ALEN),
 	[NL80211_WOWLAN_TCP_SRC_PORT] = { .type = NLA_U16 },
 	[NL80211_WOWLAN_TCP_DST_PORT] = { .type = NLA_U16 },
-	[NL80211_WOWLAN_TCP_DATA_PAYLOAD] = { .type = NLA_MIN_LEN, .len = 1 },
+	[NL80211_WOWLAN_TCP_DATA_PAYLOAD] = NLA_POLICY_MIN_LEN(1),
 	[NL80211_WOWLAN_TCP_DATA_PAYLOAD_SEQ] = {
 		.len = sizeof(struct nl80211_wowlan_tcp_data_seq)
 	},
@@ -711,8 +709,8 @@ nl80211_wowlan_tcp_policy[NUM_NL80211_WOWLAN_TCP] = {
 		.len = sizeof(struct nl80211_wowlan_tcp_data_token)
 	},
 	[NL80211_WOWLAN_TCP_DATA_INTERVAL] = { .type = NLA_U32 },
-	[NL80211_WOWLAN_TCP_WAKE_PAYLOAD] = { .type = NLA_MIN_LEN, .len = 1 },
-	[NL80211_WOWLAN_TCP_WAKE_MASK] = { .type = NLA_MIN_LEN, .len = 1 },
+	[NL80211_WOWLAN_TCP_WAKE_PAYLOAD] = NLA_POLICY_MIN_LEN(1),
+	[NL80211_WOWLAN_TCP_WAKE_MASK] = NLA_POLICY_MIN_LEN(1),
 };
 #endif /* CONFIG_PM */